Lambeth Group

The Lambeth Group is a stratigraphic group, a set of geological rock strata in the London and Hampshire Basins of southern England. It comprises a complex of vertically and laterally varying gravels, sands, silts and clays deposited between 56-55 million years before present during the Ypresian age (lower Eocene). It is found throughout the London Basin with a thickness between 10m and 30m and the Hampshire Basin with a thickness between 50m and less than 25m. Surface outcrops are present only on the outskirts of these, however, that the Lambeth Group underlies some 25% of London at a depth of less than 30m means the formation is of great engineering interest for tunnelling and foundations.